Field of the Invention
The present invention relates to systems and methods for controlling the same, network interface apparatuses and methods for controlling the same, and non-transitory computer readable medium.
Description of the Related Art
Conventionally, image forming apparatuses, such as a multi-function peripheral, a single-function printer, etc., that have a sleep mode (power saving mode) in which power consumption is less than in a standby mode (normal power supply mode), have become increasingly popular. In the sleep mode, power is not supplied to units except a random access memory (RAM), a network interface card (NIC), and an operation unit, whereby power consumption in the sleep mode is reduced to about one to several watts. Note that, in the sleep mode, power is also not supplied to a photoconductive drum or fixing unit included in a printer unit of the image forming apparatus, or a central processing unit (CPU) or a hard disk drive (HDD). Therefore, in the sleep mode, the functions of the image forming apparatus are limited, and the image forming apparatus cannot perform an image forming process.
On the other hand, when a predetermined condition is satisfied in the sleep mode, the image forming apparatus returns (resumes) from the sleep mode to the standby state. The predetermined condition is, for example, (1) the user has performed an operation on the operation unit of the image forming apparatus; (2) the NIC has received, through a network, a packet which satisfies a condition for returning from the sleep mode; etc. Therefore, power is supplied to the operation unit and the NIC even in the sleep mode to monitor pressing down of buttons included in the operation unit, reception of packets, etc. Japanese Patent Laid-Open No. 2009-504083 describes an example technique of allowing an apparatus to return from the sleep mode, in which a target which is located in a target LAN and is to be returned from the sleep mode is caused to return using a remote system through a relay agent.
Incidentally, some recent image forming apparatuses have a function of performing a job in cooperation with another image forming apparatus, i.e., a plurality of image forming apparatuses perform a job in cooperation with each other. For example, in the case of the fax reception and transfer function, image forming apparatuses perform a job in cooperation with each other. The reception and transfer function indicates that one apparatus (represented by B) which has received fax data from another image forming apparatus (represented by A) does not print the fax data on its own, and transfers the received fax data to still another image forming apparatus (represented by C) in accordance with reception and transfer settings set in the image forming apparatus B. In other words, the image forming apparatus B which has received the fax data does not perform a printing process and only transfers the fax data, while the image forming apparatus C which has received the transferred fax data performs a printing process. In recent years, an image forming apparatus which performs fax communication called IP-fax using an IP network has also become increasingly widespread.
When image forming apparatuses having the sleep mode are used to receive and transfer an IP-fax, there may be a situation in which a first image forming apparatus which first receives an IP-fax is in the sleep mode while a second image forming apparatus which is a transfer destination is also in the sleep mode. In this case, initially, the first image forming apparatus which receives an IP-fax needs to first return from the sleep mode, which is triggered by reception of a connection request packet of the IP-fax. The first image forming apparatus receives an IP-fax after returning from the sleep mode, checks the transfer-destination apparatus, and thereafter, transfers the IP-fax. Similarly, the second image forming apparatus which receives the transferred IP-fax returns from the sleep mode when receiving a transfer connection request packet.
In other words, an image forming apparatus which temporarily receives an IP-fax first returns from the sleep mode, and thereafter, begins the transfer process of the IP-fax. Only after that, the transfer-destination image forming apparatus receives the transfer data and returns from the sleep mode. Therefore, there is a time lag between the return from the sleep mode of the transfer-source image forming apparatus and that of the transfer-destination image forming apparatus.
In the technique of Japanese Patent Laid-Open No. 2009-504083 above, when the second apparatus is caused to return, the remote system sends an instruction in which a target is explicitly specified, to a relay agent. Thus, this technique is effective when a target is already definitely specified in the remote system. However, a case where a target is unknown in the sender as in the case of the above IP-fax reception and transfer (only the relay apparatus knows a party which is caused to return), is not taken into account. Also, the elapsed time until a target returns when the relay agent (relay apparatus) itself is in the sleep mode is not particularly taken into account. Specifically, in the case of the IP-fax reception and transfer, the presence of the above time lag between the return from the sleep mode of the transfer-source image forming apparatus and that of the transfer-destination image forming apparatus is not taken into account.
Therefore, the technique of Japanese Patent Laid-Open No. 2009-504083 above is effective when a target is already clearly known in the remote system, but cannot be used when a target is not known in the sender as in the case of the above IP-fax reception and transfer. Also, when a relay agent (relay apparatus) is in the sleep mode, then if the relay apparatus is caused to temporarily return and then instruct a target to return, it disadvantageously takes a long time to complete the start of the target.